Baffle structure in gaseous discharge devices



Sept.- l, 1953 w. w. wArRoUs, JR. 2,650,998

BAFFLE STRUCTURE IN GASEOUS DISCHARGE DEVICES VFiled Dec. 29, 1950 Patented Sept. 1, 1953 BAEFLE'- STRUCTURE IN- (tASEOUSA DISCHARGE DEVICE Sr 5:.C1aims.; (Cl. 313-1193 This' inventionV relates" tol gaseous' discharge de vices; generally termed' thyratrons,' andV has particularv reference to a' formA of' baille'fwhiclr is interposed betweerr the cathodel and the= control? electrode` Theuse` of' bales irrA gaseousff discharge. devices is common iir the prior-'art since thesestriictures:v are usefulE preventing' flasliebacl ork condire tienr inl the-reverse direction and also' inL prevent-- ingconduction in theater-ward r`directi'on1whenrv the contrcl-electrode-li's regulatedior non-conduction'. In* addition; the bailles-l a-reusef-'ul or'prctecting: thee anode-andi control"4 electrodefir-om` heat' radi'ax tient-rom thecathodea Tl'iepresent inventioni'sV directed@ tota structurel Whichcomprises# a baille iir` the:- form: cita; correa. Thinbaflieoccupiessa certainrvolume off thespace between the control electrode andi thecathode andi reduces; thepathi of ionized gasmoleculesg. thereby preventing:unwantedconductiona. Itlalsce performs other desirable functions whiclrawiilrbe evident"` firemf the following-.fl description..

Une of the.y objectsh on thisimfentioin.istto:l pret`r videV an improvedriesig-mot" gaseous; discharge: de vica including; a cone barile; arrangement. which. reduces thezvvolurne im the? ionized: gasa region tol' aiminimuxm.

Another object. ofz the: invention. is:4 concert..` tiratetlediscirarge betwcemthe anndes andcathi-rl ode om the.` proper: areal ofi the; control. electrndef soi that.:v the; electrostatic: feldi` ofi. thea anode.- can: easilyv initiate ionization; and: permit; ther opera@` ti'on-.ofrthe device with: ai lowentr-ggervoltagez.

Another' object on the;y invention is;A thef pno;- teetion:v oil the. control@ electrode: from; the heat. energy radiaifedbyt the cathoder. In thisemanner. the: control* electrode?. is.r reducedV ini temperature; and; primary' emission is.pr.evented.

Another object of theinvention; isftofdeiect, particleszoi emitting; material from the cathode, and keep them away from the more active areas of thecontrollelectrodee..

The invention comprises` a. gaseous discharge device having an envelope containing gas at a reduced pressure and a cathodeL which is heated tof emit' al'argcL sup-ply et electrons. A shielded anodeY is providedwhich is connected to'- a high potentialr sourcey and attractsVV electrons when the potential of' a controlI electrode is raised sufilciently positive to initiate the discharge. The

control electrode is positioned between the anode 'F and cathode for initiating the flow of electrons to the anode, and a cone-shaped baffle is interposed between the cathode and the control electrode to restrict the movement of ionized particles. The baille differs from prior art baffles in that it i electrodelill which contains' perforations'A I-'P for# thel passage=of electrons' when the tube=is inits ccnductingcondition. Attaclied tothe :shield-7 lili is' upper f dish' I-'3'- which' acts` as? a shield for arr anode.` The anode Mii@ Supported-oni a rodf t5? which issealed=` ihto` the envelopey t9 and'L acts-as the anodeconductor ae wellfv as2 ther anode sup-- port.- Dlrectly below the-control' electrodei Hf' is" a# baflle l 6i supported by twox or more brackets: l 1. Tlie=bafe1 l6 i`s`a1-dislr-shapedmemben and? itf-is: connected directlvftothel control electrode lil? and? the: shie'ldY 10i. cathode structureY 211? is: posi-r tioned" in: the1 lower part. the tube, asdally.l aligned with the shield IU, and comprsesuaplua rality. off electrrnr` emitting: vaines;V 2 i These. Varies pointsinwardly.` toward the axis` of theYY tube'- and aref. snpponted.- byf an cylindrical. memher- 22".. Irrordento: produce-largecnumbers: of electronsi from; the emitting;V surface, heat'.issapplieliA toithezcathfode structure: by a number of resistance;elementsl 23 positioned around the cylindrical member-` 2.2'.,

" These heater elements are connected to aasource of,v electrical power (not. shown). and whenA in operation, assumea temperature et about 1200.9 centgrade,I thereby keeping thecathodevanes` 2 I1 at-the proper temperature for` electron? emission.

Surrounding the heating elements 2f3r are tvs/1.o:Y shield'f membersy 2.4 and; 2-5; having-theI spa-ce be*-r tween them partly filled` with a. metallic foil 26;. which. may be nick-e1., acting: as., a heat insulator` v and preventingtheheat irorntherresistanoeele ments.. trom. being. dissipated to. the. shield. andl the envelope; Theshieldmembersldf and 2-5iare. electrically connected to. the-e cathode,- emittingh varies.y 24;.. This ornr of,V cathode has, been described: in acopending application, Serial.; Nei.

' 203,438, filed December 29, 1950, by W. W. Watrous, Jr.

Directly above the cathode vanes 2l are two heat shielding bales 30 and 3l, each with an axially aligned hole to permit the electrons to escape from the emitting surface. Some disthe outside edge of heat baille 33 to the baille iii l mounted adjacent to the control electrode. lt will be obvious that this type of baille can have several forms. For example, the baille 16 may be attached to the top portion ci the cone baille in` stead of supporting it from the grid structure, thereby providing an enclosed volume. Also, the lower flat portion of the cone baille 38 may be formed as a part of the upper heat baille s3 or the cone baille may be supported from the grid baille i5. These variations, however, in no sense detract or alter the operation of the gaseous discharge device.

When such a device is operated, the cathode structure 20 emits a large number of electrons which, with a suflicient electrical field in a rarei'led gas produces ionized gas molecules above and surrounding the cathode structure. The anode I4 may be raised to a high positive Voltage without conduction between the anode and cathode as long as the control electrode il is kept at a suitable potential. This means that there is little or no electric held extending into the gridcathode region. To initiate conduction in the device the control electrode Il is usually raised to a small positive voltage. The result is the well known anode-cathode conduction which passes current through the device. The conduction continues as long as the anode voltage is maintained and is not affected by a reduction of the control electrode potential to its former value.

When the anode-cathode electric eld is eliminated, the cone baffle rapidly eilects deionization and the electric eld may again be established without the reoccurrence of conduction. The device is then in condition for another cycle of operations.

`While there have been described and illustrated specific embodiments of the invention, it will be obvious that various changes and modications may be made therein without departing from the field of the invention which should be limited only by the scope of the appended claims.

I claim:

1. A gaseous discharge device comprising, an envelope, a gas within the envelope, a heated cathode for emitting electrons, a shielded anode within said envelope, a control electrode positioned between the anode and cathode for initially controlling the iiow of electrons between the anode and cathode, and a cone-shaped baille positioned between the cathode and the control electrode, said baille secured mechanically to the cathode and including an inclined surface which directs the flow of electrons toward the periphery of the control electrode.

2. A gaseous discharge device comprising, an envelope, a gas within the envelope, a heated cathode for emitting electrons, a shielded anode within the envelope, a control electrode positioned between the anode and cathode for initially controlling the now of electrons between the anode and cathode, and a cone-shaped baille positioned between the cathode and the control electrode with its larger end adjacent to the control electrode, said baille secured mechanically to the cathode and including an inclined surface which directs the flow of electrons toward the periphery of the control electrode.

3. A gaseous discharge device comprising, an envelope, 'a gas within said envelope, a heated cathode enclosed in a cylindrical shield with one endopen for the discharge of electrons, a shield- `ed anode within said envelope, a control electrode positioned between the anode and cathode for initially Ycontrolling the flow of electrons to the anode, and a cone-shaped baille positioned between the opening in said cathode shield and the control electrode, said baille secured mechanically to the cathode shield and including an inclined surface for directing the ilow of electrons toward the periphery of the control.

electrode.

e. A gaseous discharge device comprising, an envelope, a gas within the envelope, a heated cathode for emitting electrons, a shielded anode within the envelope, a control electrode positioned between the anode and cathode for initially controlling the flow of electrons between the anode and cathode, and a baille shaped in theform of a frustrum of a cone positioned between the cathode and the control electrode with its larger end adjacent to the control electrode and its srnallei1 end adjacent to a baille plate secured to the cathode, said frustrum-shaped baille secured mechanically to the cathode and including an inclined surface which directs the flow of electrons toward the periphery of the control electrode.

5. A gaseous discharge device comprising, an envelope, a gas within the envelope; a shielded cathode, portions of which are heated by the application of electrical energy; a control electrode positioned between the anode and cathode for initially controlling the flow of electrons between the anode and cathode; and a baille shaped in the form of a frustrum of a cone positioned between the cathode and the control electrode for reducing the effective volume between said electrodes with the larger end of the frustrum adjacent to the control electrode and the smaller end of the frustrum adjacent to a baille plate secured to the shielded cathode, said frustrumshaped baille secured mechanically to the cathode and including an inclined surface Which directs the flow of electrons toward the periphery of the control electrode.

WARD W. WATROUS, JR.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,071,057 Baruch Feb. 16, 1937 2,099,111 Hefele Nov. 16, 1937 2,301,980 Steenbeek Nov. 17, 1942 2,518,879 Germeshausen Aug. 15, 1950 

